You are troubleshooting a problem with a wireless solution that uses MQTT where the IoT...

Bottom-Up Troubleshooting: The OSI model provides a structured diagnostic approach. Starting at Layer 1 ensures basic physical connectivity issues are ruled out first.

MQTT Relies on IP: MQTT operates at a higher layer of the OSI model, relying on TCP/IP (Layers 4 and 3) for communication. Problems at the physical layer will disrupt everything built upon it.

Checking the Fundamentals: Before investigating complex application issues (MQTT), verify cables, link lights, Wi-Fi signal strength, etc.

References:

OSI Model: Descriptions of the seven layers, emphasizing the foundation provided by Layer 1 (Physical).

Network Troubleshooting Guides: Resources that outline common Layer 1 problems and their symptoms.